1. Field of the Invention
The present invention relates to a fluid pressure control device with a fluid discharge prevention mechanism used for a fuel tank having an air chamber, and more specifically to a novel and simple structure of the pressure control device, which is of a pressure vessel used with an automotive vehicle.
The fluid discharge prevention mechanism serves to prevent fuel from being discharged in an abnormal condition such as when the vehicle overturns.
2. Description of the Prior Art
The conventional pressure control device with a fluid discharge prevention mechanism usually comprises three separate chambers: a ball-housing chamber, a valve-housing chamber and an atmosphere-communicating chamber. This kind of construction has several faults. The basic problems are as follows:
(1) fuel condensed in the valve-housing chamber is easily discharged through the pressure control valve when pressure is applied thereto, since the valve housing is separate;
(2) a relatively great weight is required and the valve is closed only by a spring force, since the valve is normally kept open by the balance of the weight and the spring force;
(3) the number of necessary parts is relatively great;
(4) the shapes or profiles of the parts are complicated for a mass production process; and
(5) the cost of the parts is relatively high.
A more detailed description of the prior-art pressure control device with a fluid discharge prevention mechanism will be made hereinafter under DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS with reference to FIG. 1.